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Tax Calculator

Add tax to a price, or work out how much tax is already inside a total. Works for VAT, GST and sales tax at any rate.

Runs entirely in your browser

Please note

This is a general arithmetic tool. Tax rules, thresholds, exemptions and reduced rates vary by jurisdiction and by product. Check with a qualified accountant or your tax authority for anything official.

How to use the Tax Calculator

  1. 1Choose whether you are adding tax to a net amount or removing it from a gross amount.
  2. 2Enter the amount and the tax rate.
  3. 3Read the net, tax and gross figures.
  4. 4Use the preset rates if your country's standard rate is listed.

How it works

Adding tax multiplies the net amount by one plus the rate. Removing tax is the trickier direction, and it is where mistakes happen: you cannot take 20% off a gross price to find the net. You divide by 1.20 instead.

The difference is not small. Take 20% off 120 and you get 96; divide 120 by 1.2 and you get 100, which is the correct net figure. The tool always uses the division form when extracting tax.

All figures are rounded to the nearest cent using half-up rounding, which is what invoices and receipts use.

The formula

gross = net × (1 + r) net = gross ÷ (1 + r) tax = gross − net
net
the amount before tax
gross
the amount including tax
r
tax rate as a decimal, e.g. 0.2 for 20%

Extracting tax divides by (1 + r). Subtracting the rate from the gross price gives the wrong answer.

Worked example

A 240 invoice total that includes 20% VAT

  1. Net = 240 ÷ 1.20 = 200
  2. Tax = 240 − 200 = 40

Result: 200 net plus 40 VAT. Note that 20% of 240 is 48, which would be wrong.

Frequently asked questions

How do I remove VAT from a price?
Divide the gross price by 1 plus the rate. For 20% VAT, divide by 1.2. Subtracting 20% from the gross gives too small a net figure.
What is the difference between VAT, GST and sales tax?
VAT and GST are charged at each stage of the supply chain with credits for tax already paid; sales tax is charged once at the final sale. The arithmetic here is identical for all three.
Can I calculate several tax rates at once?
Enter a combined rate if your jurisdiction stacks state and local rates. For compound taxes charged on top of each other, use the calculator twice.

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